含脂肪链聚苯并咪唑的合成及其气体透过性能

对含脂肪链聚苯并咪唑的聚合反应进行了比较系统的研究，在此基础上，合成了一系列含脂肪链聚苯并咪唑．以甲酸为溶剂，在减压下，制备了聚合物的均质膜．对聚合物的气体选择透过性能进行了研究，并从化学结构与气体透过性能关系的角度进行了讨论，发现同一聚合物对不同气体的透过系数符合一般玻璃态聚合物的规津；增加柔性链段中亚甲基数目，可提高聚合物的气体透过系数，降低分离系数；刚性链段中引入柔性基因，可增大气体透过系数；温度升高，聚合物的气体透过系数提高，分离系数一般下降．     

图案化两亲性刚-柔嵌段共聚物薄膜的耗散粒子动力学模拟

运用耗散粒子动力学模拟,研究了两亲性刚-柔嵌段共聚物在平面基板上的自组装,考察了溶剂选择性和基板形状对自组装形貌的影响。结果表明,共聚物可以在基板表面形成多种图案(如条纹图案),其中疏水刚性链段有序排列形成条纹的内核,亲水柔性链段形成外壳。当溶剂对柔性链段亲和性较好且对刚性链段亲和性较差时可以得到具有条纹图案的薄膜。此外,共聚物可以在不同形状的基板上形成与基板具有相似拓扑结构的条纹图案。     

粘度比对刚性链高分子与柔性链高分子共混物微结构的影响

粘度比对刚性链高分子与柔性链高分子共混物微结构的影响何嘉松,卜文胜,张洪志,许向青（中国科学院化学研究所,北京,１０００８０）（化工部北京化工研究院,北京,１０００１３）关键词高分子共混物,热致液晶聚合物,聚合物加工影响柔性链高分子与柔性链高分子共混...     

刺激响应性刚柔嵌段共聚物的自组装

刚柔嵌段共聚物是指刚性链段和柔性链段以共价键相连形成的共聚物。不仅由于刚性链段有序排列的特点使得其自组装行为更为丰富多样,而且刚性分子将优异的功能特性赋予到超分子组装体中,有望实现超分子材料的功能应用。这类嵌段共聚物在溶液中自组装形成的聚集体会对外界的刺激(例如pH、光、温度、化学添加剂等)敏感,产生聚集体形态的变化。本文选取了部分典型的具有刺激响应性的刚柔嵌段共聚物,介绍了其智能自组装行为,并对其良好的发展前景做了展望。     

主链含硅的芳族聚酰胺的合成及其气体选择透过性能

采用界面缩合聚合方法，合成了一系列主链含硅的芳族聚酰胺，从化学结构与气体透过性能关系的角度研究了此类聚合物均质膜的气体透过性能，结果表明，此类聚合物膜对Ｈ２、Ｏ２、Ｎ２、ＣＯ２、ＣＨ４的气体透过系数大小顺序符合一般玻璃态聚合物规律；在刚性强的高分子链段中引进柔性基因，可提高聚合物的气体透过系数；高分子主链有较强内旋转能力的聚合物，气体透过系数大；高分子主链的化学结构相同，苯环上带有侧甲基的聚合物有高的气体透过系数；硅原子上带有侧苯基的聚合物，其气体扩散系数大于而溶解系数小于硅原子上携有侧甲基的聚合物．结论为，在刚性高分子主链中引入柔性基团和提高刚性链间隙是增大气体透过含硅聚酰胺膜速率的有利因素．     

含1,3,4-噁二唑甲壳型液晶聚合物的合成与表征

甲壳型液晶聚合物（mesogen-jacketed liquid crystal polymer,MJLCP）是1987年由周其凤教授[1]首先提出的概念.从化学结构看,甲壳型液晶聚合物属于侧链型,由烯类单体经链式聚合制得,容易得到高分子量的产物,具有一般柔性侧链型液晶聚合物的一些优点.但是与柔性侧链型液晶聚合物不同的是,MJLCP分子中的刚性液晶基元是通过腰部或重心位置与主链相联结的,在主链与刚性液晶基元的侧基之间只有很短或者没有柔性间隔基.由于在这类液晶聚合物的分子主链周围空间内刚性液晶基元的密度很高,分子主链被由液晶基元形成的外壳所包裹并被迫采取相对伸直的刚性链构象.因此,这类液晶聚合物又和主链型刚性链液晶聚合物相似,具有较明显的链刚性.近年来,周其凤课题组围绕甲壳型液晶聚合物深入开展了分子设计与合成、分子结构与性能等多方面的研究.其中,设计合成具有特定功能的甲壳型液晶聚合物是在以往研究工作和学科交叉融合的基础上发展起来的一项新的研究工作.将一些有特殊功能的基团引入到甲壳型液晶聚合物中会使其具有崭新的特性.     

线团-刚棒-线团三嵌段分子有序纳米结构的自组装

目前,在纳米科学和仿生化学等方面的一个非常吸引人的课题是构建一种新颖的、复杂的大分子或超分子体系,并通过设计连接有机嵌段单元使其具有很好的形状和功能。在线团一刚棒一线团三嵌段分子体系中,刚棒嵌段的各向异性和连接嵌段的微相分离作用导致分子自组装形成各种有序聚集体,并且通过改变柔性链体积分数、分子长度、柔性链横截面积、刚棒...     

一类新的刚性链侧链型液晶高分子的合成

以自由基聚合方法，合成了一系列含有三个苯环通过酯键相联的液晶性单体及其聚合物．在这类新的液晶高分子中，刚性液晶基元不通过柔性间隔基而直接竖挂在聚甲基丙烯酸酯大分子主链上．这些高分子有很高的玻璃化转变温度，表明其分子链刚性较大，因而代表了一类新的刚性链侧链型液晶高分子．它们的液晶行为用ＤＳＣ、偏光显微镜和Ｘ－光衍射进行了表征．发现所有单体和聚合物均为向列型热致性液晶．     

对称长链和近对称短链两嵌段聚合物混合体系相行为研究

利用自洽平均场理论(SCMFT)系统地研究了对称长链和近对称短链两嵌段聚合物混合体系在纳米尺度下的自组装行为.体系中具有较高聚合度的对称长链熔体处于层状相,聚合度较低的近对称短链熔体处于无序相,而其混合体系却随着两种成分的不同比例呈现出有序-无序相转变、有序-有序相转变及有序-无序两相共存等复杂的相行为,计算结果与近期类似体系的实验有着较好的吻合.同时与两种对称的两嵌段聚合物混合体系的计算结果进行了比较,得出这两种体系的异同之处.     

刚柔嵌段共轭聚合物自组装体系*

刚柔嵌段共轭聚合物的自组装是超分子化学研究的热点之一。本文综述了近年来刚柔嵌段共轭聚合物自组装体系研究进展。根据共轭刚性段的不同分类进行阐述,综述了聚芴,二（苯乙烯）-蒽,聚对苯撑,聚对苯乙烯撑,聚对苯撑乙炔,聚（2,5-苯甲酮）,聚噻吩,聚苯基喹啉等作为刚性链段的刚柔嵌段共轭聚合物自组装体系,介绍了刚柔嵌段共轭聚合物的合成和光物理性质;重点评述了刚柔嵌段共轭聚合物在不同溶剂、浓度、温度等条件下自组装形成一维、二维以及三维的周期性微结构,且具有方便的可控性。概括了刚柔嵌段共轭聚合物自组装体系广阔的应用前景,尤其在光电器件领域有着潜在的应用价值。最后展望了刚柔嵌段共轭聚合物自组装体系研究和发展的方向。     

Solvent effect on the aggregation behavior of rod-coil diblock copolymers

The water-induced aggregation behavior of rod-coil diblock copolymers based on poly(ethylene oxide) (PEO) and poly{(+)-2,5-bis[4'-((S)-2-methylbutoxy)phenyl]styrene} (PMBPS), PEO104-b-PMBPS53, was investigated in the common solvent THF and in the selective solvent dioxane. Before adding water, PEO104-b-PMBPS53 stayed as single polymer chains no matter what conformation the PEO block took (i.e., either the random coil conformation in THF or the compact globule conformation in dioxane). The critical water content ( approximately 6 wt %) at which PEO104-b-PMBPS53 began to aggregate was also similar in both solvents, indicating that PMBPS dominated the aggregation process. However, the size, the size distribution, and the morphology of aggregates in THF/water were quite different from those in dioxane/water. Narrowly distributed spheres with Rh approximately 20 nm were observed in dioxane, whereas in THF, a bimodal distribution peaked at 3 and approximately 300 nm, was observed. The results from 2D wide-angle X-ray diffraction and polarized optical microscopy demonstrated that the PMBPS blocks packed in a parallel pattern upon aggregation in dioxane/water. The anisotropic disclike structures observed in THF/water also indicated the orientation of the PMBPS blocks upon forming aggregates in dilute solution.     

Synthesis of a Novel ABC Triblock Copolymer with a Rigid‐Rod Block via Atom Transfer Radical Polymerization

Summary: A novel ABC triblock copolymer with a rigid‐rod block was synthesized by atom transfer radical polymerization (ATRP). First, a poly(ethylene oxide) (PEO)‐Br macroinitiator was synthesized by esterification of PEO with 2‐bromoisobutyryl bromide, which was subsequently used in the preparation of a poly(ethylene oxide)‐block‐poly(methyl methacrylate) (PEO‐b‐PMMA) diblock copolymer by ATRP. A poly(ethylene oxide)‐block‐poly(methyl methacrylate)‐block‐poly{2,5‐bis[(4‐methoxyphenyl)oxycarbonyl]styrene} (PEO‐b‐PMMA‐b‐PMPCS) triblock copolymer was then synthesized by ATRP using PEO‐b‐PMMA as a macroinitiator.

ABC triblock copolymer with a rigid‐rod block.     

Segregation of Coronal Chains in Micelles Formed by Supramolecular Interactions

Summary: Spherical micelles have been formed by mixing, in DMF, a poly(styrene)‐block‐poly(2‐vinylpyridine)‐block‐poly(ethylene oxide) (PS‐block‐P2VP‐block‐PEO) triblock copolymer with either poly(acrylic acid) (PAA) or a tapered triblock copolymer consisting of a PAA central block and PEO macromonomer‐based outer blocks. Noncovalent interactions between PAA and P2VP result in the micellar core while the outer corona contains both PS and PEO chains. Segregation of the coronal chains is observed when the tapered copolymer is used.

Inclusion of comb‐like chains with short PEO teeth in the corona triggers the nanophase segregation of PS and PEO as illustrated here (PS = polystyrene; PEO = poly(ethylene oxide)).     

Langmuir monolayer and Langmuir–Blodgett films of amphiphilic triblock copolymers with water-soluble middle block

Langmuir monolayers and Langmuir–Blodgett (LB) film morphology of amphiphilic triblock copolymers are studied using surface pressure-area measurements and atomic force microscopy (AFM), respectively. The triblock copolymers are composed of long water-soluble poly(ethylene oxide) (PEO) chains as middle block with very short poly(perfluorohexylethyl methacrylate) (PFMA) end blocks. The surface pressure-area isotherms show phase transitions in the brush regime. This phase transition is due to a rearrangement of PFMA block at the air–water interface. It becomes more significant with increasing PFMA content in the copolymer. LB films transferred at low surface pressures from the air–water interface to hydrophilic silicon substrates show surface micelles in the size range of 50–100 nm. A typical crystalline morphology of the corresponding PEO homopolymer is observed in LB films of copolymers with very short PFMA blocks, transferred in the brush region at high surface pressure. This crystallization is hindered with increasing PFMA content in the copolymer.     

Polymeric surfactants in latex technology: polystyrene–poly(ethylene oxide) block copolymers as stabilizers in emulsion polymerization

Polystyrene–poly(ethylene oxide) PS–PEO di- and triblock copolymers have been used as stabilizers in the emulsion polymerization of styrene and styrene–butylacrylate for the preparation of “hairy latexes”. The polymerization kinetics and the efficiency of these polymeric surfactants were correlated with the molecular characteristics of the block copolymer. It was shown that the efficiency decreased with increasing molecular weight and PS content of the block copolymer. The PEO frige, with a thickness of 4–25 nm, on the latex particle surface could be characterized and it was shown by differential scanning calorimetry (DSC) that water is strucured in that PEO layer. Film formation with “hairy latexes” was also examined both by DSC and thermomechanical analysis. The properties and application possibilities, such as in controlled latex flocculation, have been reviewed.     

Characterization and demulsification of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) copolymers

Four poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) copolymers with different molecular weights and PPO/PEO composition ratios were synthesized. The characterization of the PEO-PPO-PEO triblock copolymers was studied by surface tension measurement, UV-vis spectra, and surface pressure method. These results clearly showed that the CMC of PEO-PPO-PEO was not a certain value but a concentration range, in contrast to classical surfactant, and two breaks around CMC were reflected in both surface tension isotherm curves and UV-vis absorption spectra. The range of CMC became wider with increasing PPO/PEO composition ratio. Surface pressure Pi-A curves revealed that the amphiphilic triblock copolymer PEO-PPO-PEO molecule was flexible at the air/water interface. We found that the minimum area per molecule at the air/water interface increased with the proportion of PEO chains. The copolymers with the same mass fractions of PEO had similar slopes in the isotherm of the Pi-A curve. From the demulsification experiments a conclusion had been drawn that the dehydration speed increased with decreased content of PEO, but the final dehydration rate of four demulsifiers was approximate. We determined that the coalescence of water drops resulted in the breaking of crude oil emulsions from the micrograph.     

Sphere-to-rod transition of short-chain PEO-b-PDMS-b-PEO in aqueous solution induced by copolymer concentration

A short-chain triblock copolymer EO9-DMS7-EO9 was synthesized by coupling reaction of allyl-terminated poly（ethylene oxide） and Si-H-terminated poly（dimethylsiloxane）. The structure and purity of synthesized copolymer was carefully characterized. Self-assembly behavior of EO9-DMST-EO9 triblock copolymer in water was investigated. And it was found that along with the increase of copolymer concentration, morphology of self-assembled aggregates transits from sphere to rod. A plausible understanding of the morphology transition for the investigated triblock copolymer was proposed.     

A novel pathogen detection system based on high‐resolution CE‐SSCP using a triblock copolymer matrix

Although CE‐SSCP analysis combined with 16S ribosomal RNA gene‐specific PCR has enormous potential as a simple and versatile pathogen detection technique, low resolution of CE‐SSCP causes the limited application. Among the experimental conditions affecting the resolution, the polymer matrix is considered to be most critical to improve the resolution of CE‐SSCP analysis. However, due to the peak broadening caused by the interaction between hydrophobic moiety of polymer matrices and DNA, conventional polymer matrices are not ideal for CE‐SSCP analysis. A poly(ethyleneoxide)‐poly(propyleneoxide)‐poly(ethyleneoxide) (PEO‐PPO‐PEO) triblock copolymer, with dynamic coating ability and a propensity to form micelles to minimize exposure of hydrophobic PPO block to DNA, can be an alternative matrix. In this study, we examined the resolution of CE‐SSCP analysis using the PEO‐PPO‐PEO triblock copolymer as the polymer matrix and four same‐sized DNA fragments of similar sequence content. Among 48 commercially available PEO‐PPO‐PEO triblock copolymers, three were selected due to their transparency in the operable range of viscosity and PEO₁₃₇PPO₄₃PEO₁₃₇ exhibited the most effective separation. Significant improvement in resolution allowed discrimination of the similar sequences, thus greatly facilitated CE‐SSCP analysis compared to the conventional polymer matrix. The results indicate that PEO‐PPO‐PEO triblock copolymer may serve as an ideal matrix for high‐resolution CE‐SSCP analysis.     

Salt‐Induced Micellization of Pluronic F88 in Water

The effect of potassium chloride on the micellization of a poly(ethylene oxide)‐poly(propylene oxide)‐poly(ethylene oxide) (PEO‐PPO‐PEO) triblock copolymer (Pluronic F88: EO₁₀₃PO₃₉EO₁₀₃.) in water was studied by fluorescence, FTIR, ¹H NMR, dynamic light scattering, and dye solubilization. The critical micellization temperature (CMT) values of the copolymer decreased with an increase of KCl concentration while micellar core gets progressively dehydrated. The results reveal the leading role of salt‐water interaction in promoting the micellization of PEO‐PPO‐PEO copolymer by the addition of salt. No significant micellar growth was seen even at temperatures close to cloud point.